/*
 * Copyright (C) 2006 Alfresco, Inc.
 *
 * Licensed under the Mozilla Public License version 1.1 
 * with a permitted attribution clause. You may obtain a
 * copy of the License at
 *
 *   http://www.alfresco.org/legal/license.txt
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific
 * language governing permissions and limitations under the
 * License.
 */

package org.alfresco.repo.avm.hibernate;

import java.util.Iterator;
import java.util.List;

import org.alfresco.repo.avm.AVMNode;
import org.alfresco.repo.avm.AVMNodeDAO;
import org.alfresco.repo.avm.AVMNodeImpl;
import org.alfresco.repo.avm.AVMNodeUnwrapper;
import org.alfresco.repo.avm.DirectoryNode;
import org.alfresco.repo.avm.Repository;
import org.hibernate.Query;
import org.hibernate.Session;
import org.springframework.orm.hibernate3.support.HibernateDaoSupport;

/**
 * @author britt
 *
 */
public class AVMNodeDAOHibernate extends HibernateDaoSupport implements
        AVMNodeDAO
{
    /**
     * Do nothing constructor.
     */
    public AVMNodeDAOHibernate()
    {
        super();
    }
    
    /**
     * Save the given node, having never been saved before.
     */
    public void save(AVMNode node)
    {
        getSession().save(node);
    }

    /**
     * Get all the nodes owned by a Repository and make
     * them no longer point at that Repository.
     * @param rep The Repository.
     */
    @SuppressWarnings("unchecked")
    public void unreferenceRepository(Repository rep)
    {
        Session sess = getSession();
        Query query = sess.createQuery("from AVMNodeImpl an where an.repository = :rep");
        query.setEntity("rep", rep);
        Iterator<AVMNode> iter = (Iterator<AVMNode>)query.iterate();
        while (iter.hasNext())
        {
            AVMNode node = iter.next();
            node.setRepository(null);
        }
        sess.flush();
    }

    /**
     * Delete a single node.
     * @param node The node to delete.
     */
    public void delete(AVMNode node)
    {
        getSession().delete(node);
    }

    /**
     * Get by ID.
     * @param id The id to get.
     */
    public AVMNode getByID(long id)
    {
        return AVMNodeUnwrapper.Unwrap((AVMNode)getSession().get(AVMNodeImpl.class, id));
    }

    /**
     * Get those nodes which are new in the given repository.
     * @param repo The repository.
     * @return A List of AVMNodes.
     */
    @SuppressWarnings("unchecked")
    public List<AVMNode> getNewInRepo(Repository repo)
    {
        Query query = 
            getSession().getNamedQuery("AVMNode.ByNewInRepo");
        query.setEntity("repo", repo);
        return (List<AVMNode>)query.list();
    }
    
    /**
     * Update a node that has been dirtied.
     * @param node The node.
     */
    public void update(AVMNode node)
    {
        getSession().flush();
    }
    
    /**
     * Get the root of a particular version.
     * @param rep The repository we're querying.
     * @param version The version.
     * @return The VersionRoot or null.
     */
    public DirectoryNode getRepositoryRoot(Repository rep, int version)
    {
        Query query = 
            getSession().getNamedQuery("VersionRoot.GetVersionRoot");
        query.setEntity("rep", rep);
        query.setInteger("version", version);
        AVMNode root = (AVMNode)query.uniqueResult();
        if (root == null)
        {
            return null;
        }
        return (DirectoryNode)AVMNodeUnwrapper.Unwrap(root);
    }

    /**
     * Get the ancestor of a node.
     * @param node The node whose ancestor is desired.
     * @return The ancestor or null.
     */
    public AVMNode getAncestor(AVMNode node)
    {
        Query query = getSession().createQuery("select hl.ancestor from HistoryLinkImpl hl where hl.descendent = :desc");
        query.setEntity("desc", node);
        return (AVMNode)query.uniqueResult();
    }

    /**
     * Get the node the given node was merged from.
     * @param node The node whose merged from is desired.
     * @return The merged from node or null.
     */
    public AVMNode getMergedFrom(AVMNode node)
    {
        Query query = getSession().createQuery("select ml.mfrom from MergeLinkImpl ml where ml.mto = :to");
        query.setEntity("to", node);
        return (AVMNode)query.uniqueResult();
    }

    /**
     * Get up to batchSize orphans. 
     * @param batchSize Get no more than this number.
     * @return A List of orphaned AVMNodes.
     */
    @SuppressWarnings("unchecked")
    public List<AVMNode> getOrphans(int batchSize)
    {
        Query query = getSession().getNamedQuery("FindOrphans");
        query.setMaxResults(batchSize);
        return (List<AVMNode>)query.list();
    }

    /**
     * Get all nodes that have the given repository as their owning repository.
     * @param rep The Repository.
     * @return An Iterator over the matching nodes.
     */
    @SuppressWarnings("unchecked")
    public Iterator<AVMNode> getByRepository(Repository rep)
    {
        Query query = getSession().createQuery("from AVMNodeImpl an where an.repository = :rep");
        query.setEntity("rep", rep);
        return (Iterator<AVMNode>)query.iterate();
    }

    /**
     * Inappropriate hack to get Hibernate to play nice.
     */
    public void flush()
    {
        getSession().flush();
    }
}